Top 10 Undertale Bosses

The Top Ten

Sans Sans or Sans the Skeleton is a character in the 2015 RPG Undertale created by Toby Fox. He is a lazy, pun-loving skeleton who is a supporting protagonist in the "pacifist" and "neutral" routes of Undertale, and a heroic antagonist/final boss of the "genocide" route. He is known for his incredibly difficult more.

I think it's sans because the fight itself is already hard but if you add the poison then it's the hardest fight in undertale. Geez I thought he was hard enough already

Definitely the hardest boss in the game (that takes probably at least 20 or 30 tries to beat the first time) and the one with the best gameplay, with lots of different attacks that require a lot of skill and some pretty good reflexes. Also, Sans is one of the best characters in the game, and being forced to kill him is kind of heartbreaking, specially with all his dialogue throughout the fight. It’s an emotional and stressful ride that we won’t be forgetting so soon.

I don't even play UNDERTALE but he was a mii fighter in smash and since MEGALOVANIA is dope I looked him up and I am addicted to the game.#never going genocide.I spare SANS

Ok this guy is the best. Me and my friends love Undertale and we talk about it all the time... but mostly about Sans and Papyrus

Mettaton Mettaton is a character in the popular 2015 RPG game, Undertale. He is a robot with a soul built by Dr. Alphys, and is the sole television star of the underground. Mettaton is a popular character in the fanbase. His notable features include his legs, and his catchphrase "OH YESSSS!"

Mettaton is probably the funniest character in the whole game, and his final battle is certainly his climax. Starring his beautiful new body, Mettaton EX is the perfect combination of fun gameplay and funny moments and dialogues, and is also one of the most creative moments in Undertale (the idea of an audience score during the fight is brilliant)

This boss is easy, why is it here? All forms of Mettaton are easy

This boss fight is great! I enjoyed the plot twist during the battle intro, the music, and Mettaton himself.

All right! I think we were all expecting Sans but I definitely think Mettaton is the best. He also has by far the best theme song and of course the best legs.

Asriel Dreemurr Asriel Dreemurr is a character from the 2015 game "Undertale". He was created by Toby Fox. more.

Having all the souls underground? Definitely a tough, immortal boss

Easily one of my favourite final bosses ever, just due to the sheer emotion involved.

Asriel is easy to beat, because you can't die. But if you try to not die, it's very hard.

Top ten boss fights. Not top ten hardest boss fights. The only way to win is not sparing him, but saving him. His track is one of the best in the game. I'm talking about His Theme. A complete masterpiece that deserves better than in some sad comics and animation that don't have anything to do with asriel, or flowey. Also he has the sadest backstory in the game, second being Chara. He is the most powerful boss in the entire game, (He has the power of seven humans, and can erase existence) and the fight is one of the most epic in the game. Saving someone who seemed irredeemable, but definitely wasn't.

Photoshop Flowey

The most intimidating character in the game, he's hard to beat too

First thing that comes to mind: WHAT IN THE NAME OF ALL THAT IS LIFE IS THAT?! This guy has no strategy, no mercy, just pure bullet hell. The only reason I don't really consider him top 3 worthy is because he really isn't that hard (unless you're doing a no-hit run, then good luck).

I sometimes wonder what Toby Fox was on when designing this boss. Like... no sane person or someone not doing drugs would create this. There is no way.

It is the longest fight in the game, so it has to be in the top three.

Undyne the Undying Undyne is a main character in Toby Fox's 2016 RPG, Undertale. She is the heroic fishlike captain of the Royal Guard, who takes it upon herself to protect the monsters of the Underground. Her name is derived from the word "Undine", and is a pun on the word "Undying". Her most loved monsters are her mentor, more.

Here’s the second hardest boss in the game, and the one that tried to warn us about how frustrating the path we were taking was going to be. The introduction to this fight is really awesome and unexpected, because every other character you faced up to this point were instantly killed with one hit. But not Undyne. She just refused to die.

Let's face it. I can't vote for sans because I have fought him yet. And do you know why? Because I can't get past Undyne. I mean, this boss fight is an amazing fight to get stuck on and then to curl up into a ball of despair because I can't beat it.

The only character which did not die after a hit

This fish lady is the 2nd hardest boss I have ever faced in a video game!

Papyrus Papyrus is a character from the 2015 game Undertale, made by Toby Fox. He is the Younger brother of Sans the skeleton, royal guard in training, and a sentry in the town of Snowdin. Opposite to his brother, papyrus is active, loud, and full of himself; but in an endearing way. Papyrus means to become more.

I truly love the Papyrus boss fight. Bonetrousle is one of my favorite pieces of music in Undertale and it's an extremely funny fight, especially considering that his dialogue is some of the funniest. What I truly love about Papyrus is that he refuses to kill anyone, which is one of the most sweetest things in any game... EVER! Well done, Toby Fox, for such an original character.

He is such a character. I want to meet him in real life. His fight is pretty clever too.

I love this boss but there is one downside, to spare him you just have to die to him 3 times (I think)

Papyrus Is Cool And In Disbelief Too!

Asgore Dreemurr Asgore Dreemurr is a boss monster and the king of the monsters in the 2015 RPG Undertale made by Toby Fox. Asgore is the portrayed main antagonist who plans to acquire seven human souls and use their power to break the barrier that seals the monsters underground . Aspects of his character are hinted more.

The epic opening, breaking mercy, forced to fight the kindest monster in the underground, his final words, the bitter end. no other boss represents Undertale better than Asgore

He was a king for a reason

This is a boss that is not only difficult, it's a pretty emotional one. He's reluctant to fight, he can't even look at you in the eye, the music fills the atmosphere, his attacks weaken as your HP lowers, etc. enough said.

he amazing

Muffet Muffet is a character from the game Undertale. She appears in a region called Hotland, selling pastries to raise money to rent a heated limo to help the spider clan from the Ruins (who are also raising a bake sale) reunite with the one in Hotland because the spiders can't cross Snowdin.

Her song is one of the best I've heard in this game, her fight is innovative, it's fairly challenging, enough said.

You can even skip this battle. The YouTuber I watched skipped it, and I usually HATE spiders, but today I did some research...

Best boss

Muffet is so awesome. I love her song, I love her design, I just love her. period.

Best when you suddenly end a genocide playthrough!

Mad Dummy

I have bone to pick with people who think sans is the best. Awesome battle theme too.

Probrably the most original fight, because you have to use his own attacks against him to beat him.

This thing just looks funny, has great music, and overall is a really fun and hilarious boss fight. I love its attacks.


Toriel Toriel is a main character in Toby Fox's 2016 RPG, Undertale. She is an amazing blend of goat and mother.

She's definitely one of the easiest bosses, but also one of those bosses that can really pull on your heartstrings.

She tries her hardest to keep u safe and she even gives u pacifist after the fight she hugs u and I find that very sweet.I also believe that she doesn't harm u after awhile in the pacifist fight not just because your on low health but because us words r got to her and she doesn't want to harm the way that's all thanks 4 reading
PS:sorry for abriviations

The Newcomers

? Alphys NEO

The Contenders

Undyne Undyne is a main character in Toby Fox's 2016 RPG, Undertale. She is the heroic fishlike captain of the Royal Guard, who takes it upon herself to protect the monsters of the Underground. Her name is derived from the word "Undine", and is a pun on the word "Undying". Her most loved monsters are her mentor, more.

Why is she down here her genocide fight is amazing

already in list

Greater Dog

All of the dogs in the game are so cute!

Just throw a stick. Done.

Napstablook Napstablook is a secondary character from Toby Fox's 2016 RPG, Undertale. He is the cousin of Mettaton, who left him in order to become famous. Due to this, poor Blooky has crippling depression.
Snowdrake's Mother


Mad Mew Mew

A psychotic training dummy has become... An anime girl? This is a happy twist for Mad Dummy (assuming you spare Mew Mew), as if you talk to her later, you'll find that she's becoming more like the character that she appears as, and less like, well, Mad Dummy.

Reaper Bird
Lesser Dog Lesser Dog is a character from Undertale. He is part of the Snowdin Canine Unit, and is famous for his long neck.

The lesser dog is a pet like a type of dog and as amour and went you pet him it makes long neck and as a cute face and as a sword

sooo funny

Lemon Bread

This one totally gets my vote. THEY ABSORB ATTACKS! HOW AWESOME CAN YOU GET?!?

Mettaton NEO

He looks cool...


Hidden boss hard to beat

Sandra farther

So Sorry
Chara Chara is a character in the game Undertale by Toby "Radiation" Fox who is one of the seven people to fall to the Underground prior to the fall of the player character. Her name can be changed by the player and will be assumed as the player character, until the Pacifist Route when Asriel asks for the more.

Chara: greetings I'm chara yo-
Chara:but anyway gree-
Bete noire: Oh hey frisk
Betty: but I-
Chara:you should not be here betty this ain't glitchtale now move along (shoves betty out) okay where was I... oh

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